Mechanically-operated automatic chuck



May 1, A1923.. www@ 'G. C. GIIDDINGS .MECHANICALLY OPERATD AUTOMATIC CHUCK Filed Deo. 14, 1922 34 sa @l 5X' ul/:lul Wil it tu, lli tai it. n i

Application filed heer-:miner le, 1922. Serial No. 606,359.

lie it known that l. Gnonon 'Q timelines,

a citizen of the United States, residing at hipringjiield-, in the county of lliindsor and @tate ot Vermont, have invented new and us inl .improvements1n Meehan i cally-Oper ated Automatic@hecha ot which the tolli'iwnji; is a speeilicationl i i lhe nature ot this invention is a clinch tor uutmnatic machines and its object is to provide :tor a chuck of' this character automatic `operatinigmeans which are purely meehani i cal.

lleretotore pneumatically operated chucks have been used to a large extent in automatic machines, but such chucks frive considerable trouble tor the reason that the inevitable `tluctnations in the pressure oit the eonirpressed air supplied tor operating;` them time.

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aiiects their operation and occasionally `a ehuelr` will :tail to open or close at the proper Such a 'failure is a serious detect in a machine whose operation is wholly autoj matic because it is liable to result in the breakage ot tools.

lilly invention overcomes 'troubles oit the sort above mentioned by effecting opening andelosing oit the jaws of the clinch` by mechanism which is .certain and invariable in inode of operation. Preferably my mechanism consists oit positive and unyieldinn; means arranged to cause opening;` ot the chuck uws and springs arranged and oper-I ative to close them.` ith machine containing;i

that embodiment ot the invention is shown inthe drawingsl furnished herewith and described in detail in the following,` specificaw tion.

3 le' statement ot preterence or to the details oi" the particular machine so illustrated and described1 except as required by the au pen ded statements ot claim,

ln the drawings referred tn llligrure l is an elevation ot so much ot the aforesaid machine as necessary to illustrate the invention.

liiure 2 is a lone'itudinal central section' lt .will be noted, however, that my claim tor protection is notlimited by the toren'othe plan ot section passingr through the" gnudeway iior one ot the chuck jaws.

il iggure 7 is a cross section taken on line )'T )'V '1' A is---i ol -l unire 2. higrures d and 9 are, respeetivelyjan aX- iai section and iront elevation of the cam winch directly actuates the chuck jaws in their opening' and closing` movements.

iiike reference characters designate the same parts wherever they occur in all oil the iiglures.

rthe niuueral 10 represents a head having hearings il, provided with bushings or linings i3 in which rotates a tubular spindle 'lll carrying ou its liront end a chuck 15. lt is to be understood that a pulley or other drivin element is mounted upon the spindle, preferably between the bearings ll and l2, as .is usual with machine tools, said driving element beine; omitted from the drawings because not necessary to an explanation of the present invention and because the character and mode et application of operative driving; means for the spindle are well understood by those skilled in the art,

"llhe chuck is provided with aws i6, preterably three in number, which are slidably mounted in radial `Qunleways in the chuck heath said guideways having; ribs 17 to retain the jaws, is clearly shown in Figures l. G and il. t cam i8 :tor opening and closing; the jaws is arranged in the center of the clinch, head and is secured to an actuator i9 contained nuthin the forward end oit the tuiuilar spindle and adapted to move endwise therein. Said cam has inclined guideways 20 spaced contormably to the chuck jaws into which the inner ends ot said jaws enter; and the guideways and jaws have interengaging ribs and surfaces so arranged that when the cam is moved outwardly (that isu to the riirl'it withrcspect to Figures 2 and (i) the jaws are opened and when the cam is `moved inthe opposite direction the jaws are closed upon the work. The drawings `show a work piece 2l L@gripped by the jaws.

The chuck head is attached to the tubular spindle by means of a ring or collar 22 threaded upon the spindle and to which the chuclz is attached by bolts 23.

"For moving` the actuator back and forth there is provided the following mechanism: t rod 2e is fastened at one end to the actuator 19 vand passes thence to a threaded connection, at its other end, with a bar 25 iitted to slide in a tube 26 which is firmly mountedin the spindle by spacing rings 27 and 28, and projects beyond the end or the spindle. Fixed upon the protruding part of said tube, near the end of the spindle, is a plate 29, and slidingly mounted on the outer part of the tube is a sleeve 30 to which are applied plates 3l vand 32. t pin 33 passes through the sleeve 30 and the bar 25, thereby completing a rigid connection between the cam ring 18 and the sleeve 30. Springs 34, 34 are interposed between the plates 29 and 3l to exert pressure thereon, tending to push the plate 3l outwardly and retract the cam ring 18. These springs are helical and are guided by rods 35 fastened to the plate 3l and extending freely through holes in the plate 29, carrying nuts 36 on the ends which protrude from the latter plate so as to limit the retraeting ei'lect of the springs. .These nuts may be adjusted and thereby the closing movement or' the chuckjaws may be limited to diiferent points.

The plate 32 is connected by rods 361 to a. ring 37 which has a tree sliding movement on the tubular spindle and is formed with a groove 38 in which enter studs 89 (preferably provided with anti-friction rollers) projecting from arms 40, 40 which are connected to a rock-shaft 4l mounted in bearings 42 secured to the rear side of the head i0. A third arm 43 is secured to the rockshaft and carries a trundle roll 44 cooperating with a rotatable cam 45 and with a cam plate 46 thereon. The arms 40, 40 and 43 and the rock-shaft 4l comprise, essentially, a bell crank lever which transmits motion from the cam to the sliding ring 37.

It will thus be seen that when the cam plate passes under the trundle roll 44 the plate 32 and sleeve 30 are moved to the right (in respect to these drawings), thereby so moving the cam ring 18 as to open the chuck jaws. |Then, when the cam plate (or 'eqiliivalent cam protuberance) has passed the roll 44, the springs restore the mechanism to the previous condition and ca use closing of the chuck jaws on the newly placed work piece.

It will be understood that where aut0- matic machines embodying the invention' placed in the chuck automatically, but as the means ior so placing the work pieces do not torni a part ot the present invention, they are not here disclosed.

Evidently the mechanism hereinbefore described is `positive in its action of opening the chuck jaws, wherefore its operations are certain to be pertormed uniformly and accu ely at each cycle oly the machine. In particular, it is impossible tor such conditions as fluctuations in air pressure to atleet the operation oi the chuck opening and closing mechanism in any manner.

Although l have shown the mechanism as being operated positively to open the chuck jaws and through the agency olf springs to close said jaws, l may reverse this arrangement and cause Vthe jaws to be opened through the agency oi springs and closed by unyielding rigid mechanism, within the scope for which l claim protection for this invention.

What l claim and desire to secure by Letters Patent is:

fln an automatic machine tool, a rotatable chuck-carrying spindle, a rotatable and endwise movable chuck actuator contained within said spindle, a tube lixed within the spindle surrouiuling said actuator and projecting at one end trom the spindle, a spring abutment 'tastened to said tube adjacent to the end oi the spindle, a second spring abutment having a sliding engagement on the tube, and being in rigid connection with the chuck actuator, a spring interposed between the two abutments tending to move them apart, a collar surrounding the spindle, with provision lor movement endwise thereon, connections between said collar and the second abutment adapted to transmit movement from the tormer to the latter, in the opposite direction to the force application ot said spring to thc second abutment, and a cam-controlled operatingr lever ttor so moving said collar, the collar having a'shoulder, and the lever having a stud adapted to bear upon said shoulder, for imparting movement as described to the collar.

in testimony whereof I have aflixed my signature.

GEORGE C. GIDDINGS. 

